Measuring and dosing elements are ubiquitous in production, particularly in process industries. A typical task involves measuring, dosing, and weighing predefined amounts of a specific element on a weighing instrument. Precision is important in measuring the quantity of an element to achieve accuracy and so is speed in order to achieve efficiency. For example, a chemical operator has the responsibility of measuring the proper dosage of acetylsalicylic acid and corn starch in order to meet predetermined specifications for batch production of aspirin in the pharmaceutical sector. Such a job requires accuracy in order to reach a target amount so that one may continue onward to the next production batch.
Measuring and dosing devices often provide visual assistance to facilitate the measurement and dosing process. A gauge bar is a frequent form of visual aid that is provided to display measurement values. Each gauge bar may have a target marker that is visible to indicate the target amount that is needed for the current process. As an element is added to a weighing instrument, a progress bar that tracks the process of measurement fills the gauge bar until the target amount has been reached. Once reaching the target amount the process in complete and another element is placed onto the weighing device for the next production batch.
Common measuring and dosing user interfaces use a two level gauge bar approach. A first scale is used to visually represent weight values and a second scale that may be located above the first scale is used to display a magnified portion of the first scale as the progress bar reaches a target value. This type of visualization is cumbersome as a user must focus on one location, while weighing and then shift focus to the second linear gauge to acquire the target value. Furthermore, the gauge bar has different linear scales resulting in a slow speed of the progress bar in the first scale and a faster speed of the progress bar in the second scale. Such scaling complicates the task at hand as it becomes much more difficult to acquire a precise target value and needs much space for displaying two progress bars. A single gauge bar may also be used to measure and dose elements, but this would be even more difficult as the scale factor would be too small to show the details of the target value, thus making it close to impossible to reach a precise target value.